tpl/tplimpl: Always respect the browser's "do not track" setting with GA template

[jmooring]

By default, with the Google Analytics template, we do not respect the browser's "do not track" setting:

hugo/tpl/tplimpl/embedded/templates/google_analytics.html

Lines 9 to 18 in e08d9af

	if ({{ site.Config.Privacy.GoogleAnalytics.RespectDoNotTrack }}) {
	var dnt = (navigator.doNotTrack || window.doNotTrack || navigator.msDoNotTrack);
	var doNotTrack = (dnt == "1" || dnt == "yes");
	}
	if (!doNotTrack) {
	window.dataLayer = window.dataLayer || [];
	function gtag(){dataLayer.push(arguments);}
	gtag('js', new Date());
	gtag('config', '{{ . }}');
	}

I can't think of a good reason for overriding a visitor's preferences.

I suggest we deprecate this config setting and always respect the visitor's preference.

cc: @chalin

[bep]

I can't think of a good reason for overriding a visitor's preferences.

This is the script you get from Google:

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-MBZGKNMDWC"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-MBZGKNMDWC');
</script>

Many site managers will want the above, I don't think Hugo want to take a morale standpoint here.

But I do agree that respectDoNotTrack can be default true, but I don't think we can remove it.